Sensitization of photographic emulsions



United States Patent Ghice Patented June 14, 1960 2,940,855 SENSITIZATION F PHOTOGRAPHIC EMULSIONS Dorothy J. Beavers, Charles V. Wilson, and James L.

Graham, Rochester, N.Y., asngnors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey No Drawing. Filed Nov. 27, 1957, Ser. No. 699,199

17 Claims. (Cl. 96-107) This invention relates to the sensitization of photographic silver halide emulsions with certain quaternary ammonium salts, e.g., pyridinium and quinolium salts.

The sensitization of photographic emulsions with compounds containing quaternary nitrogen atoms has been known for many years as shown by the Carroll US. Patent 2,271,623, granted February 3, 1942. A representative quaternary salt sensitizing agent of that patent is the compound ethylene-bis-oxymethylpyridinium perchlorate.

We have discovered certain compounds containing quaternary nitrogen radicals which exhibit improved properties as sensitizing agents for silver halide emulsions. Emulsions containing the compounds of the invention are appreciably more stable than emulsions containing the mentioned quaternary compounds. Accordingly, upon the aging of emulsions containing the new sensitizing agents, less fog is developed and the emulsion speed is maintained. Also, photographic emulsions containing the new quaternary nitrogen compounds maintain their speed over a wider range of development conditions than do emulsions sensitized with previously known alkylene-bispyridinium salts such as decamethylene-l,IO-biS-pyridinium perchlorate. Thus emulsions containing the latter compound as a sensitizing agent can be expected to lose an appreciable amount of speed when developed with a developing solution of high sulfite content of the order of 100 grams of anhydrous sodium sulfite per liter, whereas the emulsion speed is maintained in such developers when the emulsion is sensitized With the quaternary salts of the present invention.

When the emulsions are sensitized with the quaternary salts of the invention and are used in processes of color photography, that is, in multilayer color films adaptable to the reversal process of color photography, the first development step with the usual Metol-hydroquinone developer produces less fog than when the emulsions are sensitized with other quaternary salts such as that of the above Carroll invention.

It is interesting to note that Howe and Glassett British Patent 566,314 and Vanselow and James PSA Section B, 36-40 (1935), have shown that certain quaternary nitro gen salts such as n-dodecyipyridinium bromide, n-dodecyltn'ethyl ammonium bromide, etc. are not eiiective in increasing speed when development is carried out with a p-phenylenediamine as the developing agent such as used in color photography. In fact, it is shown by these workers that development with the p-phenylenediamine developing agent in the presence of the quaternary nitrogent salts retarded the development rate. The quaternary salts of the present invention when employed in the emulsions as sensitizing agents unexpectedly do not retard development rate when development is carried out with a -phenylenediamine type developing agent.

The quaternary salt sensitizing agents of the invention are bis-quaternary salts having the following general formulas:

(I) QROOCA( COOR) Q' and (H) QRCOOA( OOCR' Q where Q and Q represent the same or difierent organic radicals containing quaternary nitrogen atoms such as 2 trialkyl ammonium salt radicals and cyclammonium salt radicals, e.g., pyridinium salt radicals or quinolium salt radicals. R and R represent the same or diiferent radicals, which may be alkylene, such as -(CH ,v and including a carbon chain separated by other atoms such as O or S, e.g.,

n and n being integers of from about 1 to 10. The total chain length of R and R must be such that the number of atoms in thelinear-chain joining Q to Q does not exceed about 30. (The term atoms as used herein refers solely to the actual elements that compose the chain and not to any groups that these elements maygcarry. For example, (CH is considered to be a 10- atom chain, the hydrogen atoms being disregarded; (CH CONH(CH is a 12-atom chain; the oxygen, and hydrogen atoms being disregarded). A compound of the above structure wherein the chain contains 34 atoms has been found not to be useful as a sensitizing agent. Likewise compounds having less than about 14 atoms in the chain are not very useful sensitizing agents the sensitizing activity of the compounds decreasing rapidly in compounds having less than about 14 or more than'about 30 atoms in the linear chain connecting Q to Q. In a preferred embodiment of, the invention, therefore, the compounds contain from about 14 to about 30 atoms in the chain.

In Formulas I and II above, group A represents a linear chain of one or more atoms of carbon Whichmay or may not contain sulfur, oxygen or nitrogen as an intermediate linkage. Since n represents the positive integers 1 or 2, when n equals 1, Formulas Land 'II represent a group of compounds having the formulas (III) QROOCAQ' (IV) QRCOOAQ When n equals 2, Formulas I and II above represent a very important class of compounds having the general formulas (V) QROOCACOOR'Q' (VI) QRCOOAOOCRQ In the above formulas the number of atoms comprising A is obviously limited by the number of atoms in groups R and R sinceas mentioned above, the total number of atoms in the linear chain connecting Q to Q must not exceed about 30. Thus, in Formulas V and VI, A may contain as many as about 24 atoms in a linear chain when R and R are methylene groups. Similarly in Formulas III and IV, A may contain about 27 atoms in a linear chain when R represents a methylene group.

Chains of carbon, nitrogen, oxygen or sulfur atoms represented by A are as follows:

norm-Q 1 bis-ester (unsym):

. 3' when n and n are positive integers of the order of 1 to 10 selected so that the linear chain between Q and Q contains from about 14 to about 30 atoms. The exampleshereinafter provide compounds in which A has been varied as above to obtain very efiective sensitizing agents. 7

Compound I:

5,12-dioxa-6,11-dioxohexadecane-1,1fi-bts (py rldinium p v perchlorate) Compound 11:

,wanders.)s am. 55.16512 1 i 1 1hadron-12,zl-dioxoaomaconmnei,sz-bis(prrmmmni 4 orate) Compound lctna uom tooownoi-i, 261m 7 Y 7,1'8-d1oxa-8,17'dioxotetracosane-1Q24-his(pyrldlnium perchlorat h Compound IV: 7

' oimiu cmnooo (ontoniono o (emu-13051151 zg'not 7,10,13,16,19-pentaoxa-6,20-dioxopentacosane-1,25-b1s- (pyridinium perchlorate) Compound V: i

p cmm uonamooownawr rotnt 2610. 7 12-ox'zi-11-oxodoeosane-1,22-bts(pyridinium perchlorate) Compound VI: W

[c.mfiwnmooogdnnE-h '26101 K 7 I,IS-dioxafiJQ-dioxotetracosane-1,24-bis (pyridininm perchlorate) .Compound'VlI: P e

[(CH!)sN(CH2)sOOC (CHz)4] V'2C7H7SOF 6,17dioxa-7,16-dioxodoc0sane 1,22-bis (trimethylammonium p-toluene sultonate) The compounds of the invention having the above formulas may be prepared as follows! 'Bis-ester '(sym):

zxnon+o1coacoc1-:-xnooonoooRx ltert. amine QROOCACOORQ .x non- -noocncoonxnooonooon lira 011..

xnoocnooon'x' V amine 3 7 j'qnooonooonto, Inverse bis-ester (sym): i

ltert. amine solved in acetone, ether addedto the the solution chilled. Beautiful white platelets (3 3.5 g.,

gradually diluting with dry ether.

' ether. 'of tiny white needles of M.P. 60-625 010 0 (CH1) C 0 Gl+2HO.(CH:)aCl

Representative bis-quaternary salts of the invention may be prepared as describedin detail below.

.undecanoyl chloride added slowly to the mixture, keeping the temperature at After stirring for two hours, the benzene solution was slum'ed with 100 of water. The benzene layer was concentrated on the Rinco evaporator to yield a yellow oil which solidified upon cooling, M.P. -32% The ester may separate from the benzene solution when washing with water. The solid was discloud point, and

76 percent), M.P. 34-36" were obtained. 7

Analysis.Calc. for C H BrClO C, 57.3; H, 9.1;

Br, 18.2. Found: C,58.0;-H, 9.0; Br, 17.8.

12-oxa-11-oxodocosane-1 ,22-bis(pyridi ni um perchlorate) sHrN (b) 2NaClO4 7 C5H5N+(CH7)100 O 0 (CH1) mN C 5H5 2010A Thirty ml. of pyridine and 10.0 g. '(0.023 mole) of 1-bromo-22-chloro-l l-oxo-lZ-oxadocosane were refluxed together for two hours. The excess pyridine was removed on the steam bath under vacuum, leavingayellow oil. The oil was dissolved 'in 10ml. ethanol and dry ether added to precipitate the product as a yellow oil.

01(0119100 O 0 (CH2) mBr 'The solvent was decanted and the purification repeated.

The yellow oil was dissolved in 25ml. of -methanol, and a solution of 7.7g. (0.055 mole) of sodium perchlorate monohydrate in ml. of methanol was added, and the solution concentrated on the steam bath to about 25 ml. Acetone was added and the inorganic salt filtered 0:6. 7 p P y The filtrate, was chilled in ,Dry-Ice-acetone' while A white crystalline solid, M.P. 54-57 (cloudy), was filtered off. The solid was dissolved in acetone, filtered to remove any traces of inorganic salt, and the clear solution chilled while adding After two recrystallizations, 9.7 g. (62 percent) were collected. The product gave a clear foaming solution in water. An analytically pure sample was obtained from acetone-ether. Analysis-Cale. for C H N Cl O C, 54.6; H, 7.3; N, 4.1. Found: C, 54.1; H, 7.5; N, 4,0.

BIS-ESTER SYM) (COMPOUND n1 7,18-dioxa-8,I7-dioxotetracosane-1,24 dichloride V ouonmooowmnooownmolwnoi l-lexamethylene chlorohydrin (27.3 g.,'0.20 mole) was dissolved in 50 ml. of dichloromethane in a 300-ml. flask equipped with stirrer and dropping funnel. I Sebacyl chloride (24,g., 0.10; mole) was added slowlythroughthe dropping funnel; the temperature rosette 4 0". The: solvent was allowed to distill oti carrying with it the hydr Additional solve to escape alon'g" with the rema' I'hepale yellow oil was dissolve in 100 ml. of ethenand washer water to remove'any hydrogen chloride in the product. The ether layenwas dried over sodium sulfate: e Upon removal of the ether,

ing hydrogen chloride.

, a light yellow oil was obta iudwhich crystallized upon chilling in'anice bang." The white sand; 11 simm .'j.i..l'.i'.l 1.1. 1,

cent); melt ed arm-'1 s"; 1 #1 oil.

7,] Shams-8,17 dioxoterracosane 1,24 bfs(pyridinizm1 perchlorate) (a) 2C5H5N A mixture of 25 ml. of pyridine and 11.0 g. (0.025 mole) of the bis-ester above was refluxed for six hours. The excess pyridine was removed on the steam bath under vacuum. Methanol was added to the orange oil and this removed under vacuum to eliminate last traces of pyridine. The oily pyridinium chloride was then dissolved in 25 ml. of methanol, heated to boiling, and treated with a hot solution of 8.4 g. (0.06 mole, 20 percent excess) of sodium perchlorate monohydrate in 25 ml. of methanol. Immediately sodium chloride precipitated from the reaction and was ifltered oil. The mixture was concentrated to about 20 ml., cooled, and the remaining sodium chloride filtered off. The methanol solution was chilled in a Dry Ice-acetone bath with vigorous scratching while ether was slowly added. A white solid precipitated from solution. The solid was dissolved in acetone and crystallized by chilling in a Dry Ice-acetone mixture, 12.9 .g. (72 percent; melting point 112- 115"). An analytical sample of the bis-ester was obtained by repeating the crystallization. The melting point was unchanged.

Analysis-Cale. for C H N Cl O C, 53.0; H, 6.9; N, 3.9; Cl, 9.8. Found: C, 53.1; H, 7.1; N, 3.7; Cl, 10.8.

Compounds I and 11 are prepared similarly by use of the corresponding chlorohydrin and diacid halide.

COMPOUND IV 7,] 0,13,] 6,-19-penfora-6,20-diaxopentacosane- 1,25-dibromide COMPOUND V 7,] 0,13,] 6,] 9-pentoxa-6,20-dioxopentacosahe- 1,24-bis(pyridinium perchlorate) In a 100-ml. flask, 20 g. (0.036 mole) of 7,10,13,16 ,19- pentoxa-6,20-dioxopentacosane-1,25-dibromide (above) and 50 ml. of pyridine were refluxed for 4 hours. The excess solvent was removed on the steam bath under vacuum. The dark orange oil was slurried several times with ether, and the etherdecanted in order to remove traces of pyridine in the oil.

A small sample, 4.0 g. of the above pyridiniiun bromide, was dissolved in 20 ml. of methanol and added to a solution of 1.8 g. of sodium perchlorate monohydrate in 25 ml. of acetone. The solution was concentrated to a sticky yellow residue. Treatment with acetone dissolved the quaternary salt. The insoluble sodium bromide was removed by filtration. On removal of the acetone there was obtained 3.6 g. (86 percent) of a tan water-soluble Analysis.Calc. for c,,H, c1 N o,.-,= c, 48.3; 6.2;

N, 3.8; Cl, 9.5. Found: C, 47.5; H, 6.8; N, 3.6; Cl,-.1.0.1.

COMPOUND VI To a solution of 8.7 g. (0.05 mole) of 1,10-decanediol and 14 g. of triethylamine in 50 rnL-of benzene and 250 ml. of dichloromethane was added 21.3 'g. (0.10

moleloi w-bromocaproyl chloride in 60 ml. of benzene. The addition was rapid enough to maintain gentle refluxing. The mixture was allowed to stand for 48 hours, during which time triethylamine hydrochloride had precipitated and it was filtered off. The product was concentrated to a yellow residue on the steam bath under vacuum. Approximately 150 ml. of water were added to the syrup, and the ester extracted with three 200-1111. portions of ether. The ethereal extracts were dried over sodium sulfate. The bis ester (20 g., 76 percent) was obtained as a pale yellow oil, M.P. 2.

Analysis.Calc. for C H Br O C, 50.0; H, 7.6; Er, 30.3. Found: C, 52.5; H, 7.8; Br, 26.6.

7,18-dioxa-6,l9-dioxotetracosane-1,24- bis (pyridinium perchlorate) A solution of 10 g. (0.019 mole) of 7,18-dioxa-6,19- dioxotetracosane-1,24-dibromide (above) and 25 ml. of dry pyridine was refluxed for 4 hours. The excess pyridine was removed on the steam bath under vacuum. The oil was slurried with ether several times, and the ether decanted to remove traces of pyridine. The oily salt was then dissolved in 30 ml. of methanol. This solution was added to a solution of 6.4 g. sodium perchlorate monohydrate in 50 ml. or" acetone. The mixture was concentrated to about one-half the original volume and 50 ml. of acetone added. The sodium bromide precipitate was filtered oil. The solution was chilled in Dry Ice-acetone with scratching and ether slowly added. The sticky, semisolid that formed was redissolved in 20 ml. of methanol and the above treatment repeated twice, giving 10 g. of white solid, M.P. 65-675"; softens 55 (73 percent).

An analytical sample was obtained from methanolethanol after'two recrystallizations, M.P. 79.5-81.0".

Analysis.-Ca1c. for C32H50C12N20121 C, H, N, 3.9; Cl, 9.8. Found: C, 54.5; H, 6.9; N, 4.6; Cl, 10.0.

COMPOUND VII 6,17-dioxa-7,16-di0x0d0c0sane-L22-bis(dimethylamine) Ten milliliters of triethylamine and 5.2 g. (0.04 mole) of dimethylaminoamyl alcohol were dissolved in ml. of dry ether. A solution of 4.8 g. (0.02 mole) of sebacyl chloride in 50 ml. of ether was slowly added. The resulting slurry was allowed to stand 48 hours. The precipitatedtriethylarm'ne hydrochloride was filtered OE and the solvent removed under vacuum. The oil was dissolved in ether, washed with water, and the ethereal solution dried over sodium sulfate. Concentration of the solution gave 68 g. (79 percent) of ayellow oil of M.P. 13 to 14.

Analysis-Cale. for C H N O C, 67.2; H, 11.2; N, 6.5. Found: C, 63.9;1-1, 11.3; N, 6.3.

The analysis indicates that an amine hydrate may have formed.

6,1 7-di0xa-7 ,1 d-dioxodocosane-l ,22-bis- ('trimethylcmmonium p-toluenesulfonate) To a solution of 3.6 g. (0.0084 mole) of 6,17-dioxa- 7,16-dioxodocosane-1,22-bis(dimethylamine) above, 3.5 g. (0.018 mole) of methyl p-toluenesulfonate in 25 ml. of ethanol was added. After the exotherm had subsided, the solution was refluxed for an hour on the steam bath. The solution was concentrated to about 15 ml. and ether slowly added with chilling in an ice bath. A sticky, white, hygroscopic solid formed. The solid was dissolved in 20 ml. of methanol, chilled, and ether slowly added with scratching. The white solid thus obtained was recrystallized again' in the above manner to yield 3.0 g. (45 percent) of'a hygroscopic solid of M.P. 144-146".

A hygroscopic analytical sample of M.P. 143-145 was obtained from a methanol-ethanol solvent.

Analysis-Cale. for C H N O S C, 60.0; H, 8.5; N, 3.5; S, 8L0. FoundzC, 56.9;1-1, 8.6; N, 4.1; S, 8.1.

The following example illustrates the use of the bisof the bis-quaternary nitrogen comp except that the addenda shown is l I V Exim ml 'Ahigh-speed bromoiodide emulsion was prepared chemically sensitized with sulfur and 'gold compounds and optically sensitized with a cyanine dye. The amounts ounds' shown in the table below were added tosample's ofthe emulsion alone and together with an azaindene stabilizing agent. f The emulsion samples were then coated,jexposed on a sensitometer and developed for 5 minutes. at 68 F. in the developer given below. The speed, gamma and fog values obtained by sensitometric evaluation'of thedeveloped samples are alsoshown in thetable. ,The speed values shown are expressed as 100(l-log E) where E meter candle seconds required to prois the exposure in duce in the emulsion a density of 0.3 above fog;

Water cc.. 500 Elon ...g1-ams 2.5 Sodium sulfite anhydrous do, t 370.0 Hydroquinone d 2.5 Sodium metape'rborate do 10.0 Potassium bromide do..' 0.5 TABLE I Number Feature 1 Speed 1 Fog 4243 Control 312 1.05 0.16 4253--.... 5,12-Dloxa-6,11-dloxohexadeeane-L16- 331 1.20 .17

bi7s(p 17r1dtnium perchlorate) (I) 0.75

.4255 -Hydr xy-d-methy1-l,3,3a,7-tetra- 326 1.20 .14

zaindene (XXX) 3.0 g./m 4265 (XXX) 3.0 g.lmol+(I) 0.75 g./mol 338 1.33 17 4266 (XXX) 3.0 g.l mol+(D 2.25 g./mol 345 1. 24 .18

. M ExAh/IPIiE Z i Emulsions were'prepared and tested as in Example 1 except that the addenda shown in Table II were added.

- TABLE II Number Feature Speed 7 Fog s11 Control 318 1.29 0.20 914 7,l8-Dloxa-8,l7 dioxotetracosaned,24- 343 1.00

bis(pyridln1um perchlorate) (HI) I 0.75 gJmol. J i-Hydroxy-6-methyl-1,3,3a,7-tetta- .325 1.31 .1 zaindene (XXX) 3.0 g.'/mol. (XXX) 3.0 gJmOl-HIII) 0.75 gJmol--- 4 354 1. 05 25 (XXX) 3.0 g./mol+(III) 2.25.g.lmol 351 1.16 27 (XXX) 3.0 g.lmol+PEG 1,500- '342 1.19 .20

. (XXXI) 0.75 g./mol. y

(X X) 3.0 g., mol+(X XXI) 0.75 359 1.83 .32 1g./mol+(l'11) 0.75'g./mol.

Sample 943 shows that additional speed increase may be obtained by addition of a polyethylene glycol .of average molecular weight of 1500 (PEG l500)','or similar polyalkylene oxides having molecular weights greater than about 300. V EXAMPLE 3 Emulsions were prepared and tested as in'Example 1 v except that the addenda shown in Table 111 were added.

' TABLE III Number Feature Speed '7 Tag 5531"". ControL. 314 ifos 0.17 5545 7,10,13,16,19-Pentoxa-6,20-dioxopenta- 332 1.34

cosane-1,25-bis(pyrldlnium perchlorate) (IV) 0.75 g./mo1.'

5546-4... 4-Hydroxy-6-methyl-l,3,3a,7-tetra- 326 1.36 .18 zaindene (XXX) 3.0 g./r.nol. v

5560 (XXX) 3.0 gJmol-HIV) 0.75 g./mol 339' 1. 32 5561.;.... (XXX) 3.0 g./mol+(IY) 2.25 g./mol 342 1.29v '22 EXAMPLE4 r Emulsions were prepared and tested as in Exa'mpl e 1 Table IV were added.

TABLE IV Number Speed I Feature Control 1. 20

120xa-11-oxodocosane-L22-bis-(pyridiniurn perchlorate) (V) 0.75 g.lmol.

4 Hydroxy 6 methyl 1,3,3a,7 tetraazindene (XXX) 3.0 g./mol.

(XXX) 3.0 g./rnol+(V) 0.3 g./mol

(XXX) 3.0 g./mol+(V) 0.75 g./mol I EXAMPLE 5 V sion received no further was added one of the compounds described below. portions were coated on film support, and the dry 'were exposed to red light in an intensity scale sens eter. The exposed 'color process 1 and with the results shown in the following table. The

treatment; to another portion Both films itomfilms were processed in the reversal the 5248 negative color process 2 color process 2 was carried out as described by Hanson and Kisner ISMPTE' 61, 667-701 (1953),

for the color negative film, type 5248, involving the steps of color development, fixation, silver process 1 was carried out at 75 F. .as follows:

1. Negative development '35 2. Reversal flash exposure.

3. Color development bleaching and final fixation. Color minutes 10 minutes. 15

4. Silver bleaching do 8 5. Fixing do 3 40 The negative developer had the following composition: Water, 90 F. (32 C.) '..liter 1.0 Sodium hexametaphosphate grams 2.0 N-methyl p-aminophenol sulfate do 6.0

5 Sodium sulfite, desiccated do 50.0 Hydroquinone; do 6.0 Sodium carbonate, monohydrate; ;;do 35.0 Potassium bromide -do 2.0 Sodium thiocyanate do 1.5

0.5% solution (6-nitrobenzimidazole nitrate) ..cc 12.0 10.0

0.1% solution of potassium iodide; cc

The color developing solution above had the following a. at... mama solution above has the followin 1 '70 composition:

The fixing baths above had the following composition:

Water, 80 F. 27 O c. liter 1.0 Sodium thiosulfate do 150.0 Sodium bisulfite do 20.0

TABLE V Color Proc- Color Process 1 ess 2 (5248 Number Feature (Reversal) Negative) Speed Speed Increase Increase (A Log E) 1 (A Log E) 2 19637"-.. Control 19645- Compound I 4.0 g./mol AgX +0.14 +0.18 196.37... Control 19646- Compound II 2.0 g./mol AgX +0. 05 +0.08

1 Determined by measuring the shift of the reversal dye curve on the Log E axis at a given density below maximum density.

3 Determined by measuring the shift of the negative dye curve on the Log E axis at a given density above minimum density.

EXAMPLE 6 Emulsions were prepared and tested as in Example 1 except that the addenda shown in Table VI were added.

TABLE VI Number Feature Speed 7 Fog 180,576 Control 293 1. 04 0. 14 180,582.-. 7,18-Dioxa-6,19-dloxotetracosane-l,24- 1. O3

bis(pyridinium perchlorate) (VI) .75 g./mol AgX. 180,584.. 4- Hydroxy 6 methyl 1,3,3a,7 tetra- 298 1. 28 13 zaindene (XXX) 3.0 gJmol AgX. 180,593- (XXX) 3 g /mol+(VI) 0.15 g lmol.-. 31 1. 22 16 180,594.-. (XXX) 3 0 g /mo1+ (VI) 0.75 gJmol-.- 313 92 18 180,595.. (XXX) 3.0 g./mol+(VI) 3.0 g./mol 337 94 28 188,629 Control 306 1.10 14 188,635.- 6,17-Dioxa-7,lfi-(lioxodocosane-LZZ-bis 321 1.10 11 (trimethyl amnonium p-toluene sulfonate) (III) 0.75 g./mol AgX. 188,658.-- 4-Hydroxy-G-methyl-l,3,3s,7-tetra- 313 1. 08 14 zaindene (II) 3.0 gJmol AgX. 188,649... (11) 3.0 g./mol+(IH) 0.75 g./mol 817 1.15 15 188,650.- (II) 3.0 gJmOl-l-(III) 3.0 g./m0l 321 1.10 15 182,218 Control 303 1. 26 12 182,220..- 4,13-Di0xo-3,14-dithial1exadecane-1,16- 311 1. 26 18 bis (diethylmethylammonium px-tguene sulionate) (IV) 0.15 gJmol g 182,239.. 4 -Hydroxy -methyl- 1,3,3a,7 tetra- 305 1. 06

zaindene (II) 3.0 g./mol AgX. 182,251-- (H) 3.0 gJmoH-(lv) 0.03 gJmol 310 1. 24 12 182,250... (II) 3.0 g./mol+ (IV) 3.0 gJmol 313 1. 14 22 The bis-quaternary salts described above can be used in emulsions in the manner of the examples in concentrations of the order of about 0.02 to 4 grams per mol of silver halide.

The emulsions may also be developed in the presence of the bis-quaternary salts by incorporating the salts into a developer solution. For example, when Compound I was incorporated into the negative developer (2 g. per liter) of color process 1 of Example 5 and a multilayer color film the emulsions of which contained coupler compounds was developed therein, speed increases were obtained particularly for the red-sensitive emulsion layer.

As indicated in the above examples, it may be desirable to incorporate a stabilizing agent into the emulsion sensitized with the bis-quaternary salts of the invention to reduce fog to normal levels. Azaindenes particularly suitable for this purpose are those described in the Carroll et al. U.S. patent applications Serial Nos. 627,135 and 627,136, filed December 10, 1956, for example, the following:

5-carboxy-4-hydroxy-1,3,3a,7-tetrazaindene,

1,2-bis(4-hydroxy 6 methyl 1,3,3a,7 tetrazaindene-S- yl)ethane,

l,2,3,4-tetrakis(4-hydroxy 6 methyl-1,3,3a,7-tetrazaindene-Z-yDbutane,

2-amino-5-carboxy-4-hydroxy-1,3,3a,7-tetrazaindene,

4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene,

4-hydroxy-2-p-hydroxyethyl 6 methyl 1,3,3a,7 tetrazaindene,

10 5-carbethoxy-4-hydroxy-1,3,3a,7-tetrazaindcne, 7-hydroxy-1,2,3,4,6-pentazaindene, 2,4-dihydroxy-6-mcthyl-l,3a,7 triazaindcne, 4-hydroxy-2' -hydroxypropyl 6 methyl 1,3,3a,7 tetrazaindene and 4-hydroxy-2-(4-pyridyl)-6-mcthyl-1,3,3a,7-tetrazaindene.

The preparation of silver halide emulsions involves three separate operations: (1) the cmulsification and digestion or ripening of the silver halide, (2) the freeing of the emulsion from aqueous soluble salts usually by washing, (3) the second digestion or after-ripening to obtain increased sensitivity (Mees, The Theory of the Photographic Process, 1942, page 3). The sensitizing agents may be added at any stage, preferably after the final digestion.

The photographic emulsions which we use are of the developing-out type and best results have been obtained with gelatino-silver bromoiodide emulsions. However, emulsions of varying silver halide content may be used.

T he emulsions are chemically sensitized by any of the accepted procedures in addition to sensitizing with the bis-quaternary salts of the invention. The emulsions may be digested with naturally active gelatin, or sulfur compounds may be added such as those described in Sheppard U.S. Patents 1,574,944 and 1,623,499, and Sheppard and Brigham U.S. Patent 2,410,689.

The emulsions may also be treated with salts of the noble metals such as ruthenium, rhodium, palladium, iridium and platinum, all of which belong to group VIII of the periodic table of elements and have an atomic weight greater than 100. Representative compounds are ammonium chloropalladate, potassium chloroplatinatc and sodium chloropalladite, which are used for sensitizing in amounts below that which produces any substantial fog inhibition, as described in Smith and Trivelli U.S. Patent 2,448,060, and as anti-foggants in higher amounts, as described in Trivelli and Smith U.S. Patents 2,566,245 and 2,566,263.

The emulsions may also be chemically sensitized with gold salts as described in Waller and Dodd U.S. Patent 2,399,083 or stabilized with gold salts as described in Damschroder U.S. Patent 2,597,856 and Yutzy and Leermakers U.S. Patent 2,597,915. Suitable compounds are potassium chloroaurite, potassium a-urithiocyanate, potassium chloroaurate, auric trichloride and 2-aurosulfoben zothiazole methochloride.

The emulsions may also be chemically sensitized with reducing agents such as stannous salts (Carroll U.S. Patent 2,487,850), polyamines such as diethylene triamine (Lowe and Iones U.S. Patent 2,518,698), polyamines such as spermine (Lowe and Allen U.S. Patent 2,521,925), or bis-(fl-aminoethyl) sulfide and its watersoluble salts (Lowe and Jones U.S. Patent 2,521,926).

The emulsions may also contain polyalkylene oxides and derivatives thereof such as the polyethylene glycols, in addition to Fe bis-quaternary compounds of the invention. Suitable polyalkylene oxides and polyalkylene oxide derivatives are described in Blake U.S. Patent 2,441,389, May 11, 1948, Blake et al. U.S. Patents 2,400,532, May 21, 1946, 2,423,549, July 8, 1947, and Jennings et a1. U.S. Patent 2,577,127, December 4, 1951.

Other compounds useful for suppressing the fog level of the emulsion sensitized with the bis-quaternary compounds of the invention include the mercury compounds of Allen et al. U.S. Patent 2,728,663, Carroll and Murray U.S. Patent 2,728,664 and Lcubner and Murray U.S. Patent 2,728,665, granted December 27, 1955, and the organic mercury compounds of Carroll et a1. U.S. Patent 2,784,090, granted March 5, 1957.

Other stabilizing agents may be added to the emulsions containing the bis-quaternary salts such as the metal inorganic salts of U.S. patten application Serial No. 493,047, filed March 8, 1955, by J. E. Jones.

The chemical sensitizing agents and other addenda which we have described may be used in various kinds '1 1 12 of photographic emulsions, e.g,, various silver salts, may .WhflIiQQ nd,Q'. e'ac h represent radicals of the class he used as the sensitivesalt such as silver bromide, silver jc'onsisting ot iodide, silver chloride or mixed silver halides such as 1 1 silver chlorobromide or silverbromoiodidel a p s.

The dispersing agent for the silver halide may be 5 gelatin 'or other hydrophilic'material such as, collodion, albumin, cellulose derivatives or synthetic resins. n a a, 1 1 s 1 w Since the coupler containing emulsions sensitized as t I q -1i z described with the bis-quaternary salts are'ada'pted parl V I iticula'rly, foruse in color photography, they will ordi- .10 wherein R, R and R represent lower alkyl groups, Z

vriarily comprise the emulsion layers of multilayer color represents the atoms necessary to complete a heterocyclic films which emulsion layers are customarily differentially nucleus of the class consisting of pyridim'urn and sensitized to the primary regions of the visible spectrum q inolinium, R and R each represent alkylc g p fand contain coupler compounds producing dye-images of linked directly to the quaternary nitrogen atoms-of said colors complementary to the sensitivity of theemulsion l5 radicals, n represents'a positive integer ot fromlito 2, layers In. a representative color -film, one or more'of A represents} member of the class consistingof the-odifierentiall'y sensitized emulsion layers may be sensi- I o H )1. 1" T f""j'f 'nzod with the bis-quaternary salts, and in atypical exi i fample,'emulsions sensitized to the red, green and blue -jgfifigfigfifififigfi regions of the 'spectrum are superimposed on the support 9 i) f (Q :)v-

' I)i-i'(GH1)n' in that order-and contam cyan, magenta and yellow V color-forming coupler compounds respectively. A yellow i i ia' m flfl filter layer such as yellow colloidal silver is advani I i tageously interposed between the blueand green-sensitive (CH,).,- emulsionlaye'rs I g a I t 2 ,7 a (CHMMQW ,A,

Since the emulsion layers sensitized with the bisquaternary salts of the invention may contain coupler a a a v 1 M211. compounds they can be readily processed bywell known 7 7 g A *m ethods to yield color negatives directly or positive imand V V a 1,:

ages by means of well knownreversal processes. That is, after initial exposure of the emulsion'to a subject a developer of the p-phenylenediamine type will produce a colored image negative in respect to the subject. Likewise; if development of the emulsion layer is first car'- ried out with a non-color-forming developer followed by h i d i'cpl eseit i i int s from reversal exposure of the residual silver halide and then b t 1 t 10, th e b i f o about 14 to about 30 -color development, a colored positive is obtained as de-v atoms present in the shortest linear ch i f atoms li k.

scribed in the examples above. 1 The coupler compounds used in thetemulsionl layers sensitized with'the bis-quaternary salts, are any. of'the ing said quaternary nitrogen atoms.

. 2. A photographicsilver halide emulsion containing 40 a quaternary ammonium salt havingthe general formula well known compounds which combine with the oXida- -'tion product of primary aromatic amino (p-p henylene QRQOCACQOR'Q ,diamines) silver halide color developing agents to form wherein Q and Q' each represent'radicals of the-class Qdyes, tor example, the phenolic couplers of .U.S.'Patents consisting of 2,2 ,452, 2,362,598, 2,589,004, 2,474,293, 2,521,908, 7 r r I 2, 23,730 and Fierke US. Patent application Ser.'No. 4/ V :476,561, the pyrazolone couplers of U.S.-Patents 1,969,- if. T 1.: t: 1 'T Q 1" ;47 9,2,s69,4s9,' 2, 00,788, 2,618,641, 2,511,231 and the 1 1 7' e 1 open chain reactive methylene couplers of US. Patents and I 1. J'. 1 i 1: 2,298,443, 2,652,329, 2,407,210, 2,271,238 and McCros- V sen et al. U.S.patent application Serial No. 575,099, fil ed i E 1 1-K w 1 March 3Q, 1956. Likewise, the emulsions may contain f i i g i fe s j cploredcolor-forming couplers as described in US. Patwherein R R and R represent lower alkyl groups, Z

132,521,908, 2,706,684, 2,455,169, 2,694,703, 2,455,170 represents the atomsnecessary to completea heterocyclic and;'2,4 53,661. nucleus of the class consisting ofipyridinium and quinoi The couplers may be dispersed in the emulsion layers linium, R and R? each represent alkylenegroups linked of means of an oily coupler solvent according to the "directly to the quaternary nitrogen atomsof said radicals,

:rnethodsof U.S. Patents2,304,940 and 2,322,027. How- A'representsan alkylene groupfoffrom 1 .t'o -lQfcarbn .ieverfif as'may be the case, the couplers contain solubili z- 6 atoms, ;there being from abo'utgl4 to about 30 atoms ing groups such' as SO H groups which render the coupresent in the shortestchainofatomslipking said nitro plerssolublein alkaline solution, the oily coupler solvent gen'atoms. 1 a r I t s may be dispensed with, and the couplers can be added to 3. A photographic silver halide emulsion-containing a the emulsionsfrom aqueous solutions as their alkali metal quaternary ammonium salt having the generaliormula salts. I Y i Whatweclaimis: l V V V s 1 i 537i: 5

1. A photographic silver halide emulsion containing a e n Q and Q each represent radlcals Qt t slw quaternary ammonium salt having a general formula of I1Slstmg of 1., .2 I o o g wherein R R and R represent lower alkyl groups, Z represents the atoms necessary to complete a heterocyclic nucleus of the class consisting of pyridinium and quinclinium, R represents an alkylene group linked directly to the quaternary nitrogen atom of said radical, A represents an alkylene group of from 1 to carbon atoms, there being from about 14 to 30 atoms present in the shortest linear chain of atoms linking the quaternary nitrogen atoms of said radicals.

4. A photographic silver halide emulsion containing a quaternary ammonium salt having the general formula wherein Q and Q each represent radicals of the class consisting of wherein R R and R represent lower alkyl groups, Z represents the atoms necessary to complete a heterocyclic nucleus of the class consisting of pyridinium and quinolinium, R and R each represent alkylene groups linked directly to the quarternary nitrogen atoms of said radicals, A represents an alkylene group of from 1 to 10 carbon atoms, there being from about 14 to about 30 atoms present in the shortest chain of atoms linking said nitrogen atoms.

5. A photographic silver halide emulsion containing the compound 5,12 dioxa 6,11 dioxohexadecane 1,16- bis (pyridinium perchlorate).

6. A photographic silver halide emulsion containing the compound 7,18 dioxa 8,17 dioxotetracosane 1,24- bis(pyridinium perchlorate).

7. A photographic silver halide emulsion containing the compound 7,10,13,16,19-pentaoxa-6,20-dioxopentacosane-1,25-bis (pyridinium perchlorate).

8. A photographic silver halide emulsion containing the compound 12 oxa 11 oxodocosane 1,22 bis (pyridiniurn perchlorate).

9. A photographic silver halide emulsion containing the compound 7,18-dioxa-6,19-dioxotetracosane-l,24-bis- (pyridinium perchlorate).

10. The emulsion of claim 1 further containing a coupler compound reactive with the oxidation products of a p-phenylenediamine silver halide developing agent to form a dye.

11. The emulsion of claim 2 further containing a coupler compound reactive with the oxidation products of a p-phenylenediamine silver halide developing agent to form a dye.

12. The emulsion of claim 3 further containing a coupler compound reactive with the oxidation products of a p-phenylenediamine silver halide developing agent to form a dye.

13. The emulsion of claim 4 further containing a coupler compound reactive with the oxidation products of a p-phenylenediamine silver halide developing agent to form a dye.

14. The emulsion of claim 2 further containing an azaindene stabilizing agent.

15. The emulsion of claim 3 further containing an azaindene stabilizing agent.

16. The emulsion of claim 4 further containing an azaindene stabilizing agent.

17. The emulsion of claim 1 wherein the silver halide is sulfur and gold sensitized.

References Cited in the file of this patent UNITED STATES PATENTS 2,271,623 Carroll Feb. 3, 1942 2,288,226 Carroll et al June 30, 1942 2,419,975 Trivelli et a1 May 6, 1947 2,784,090 Carroll Mar. 5, 1957 FOREIGN PATENTS 115,971 Australia Oct. 15, 1942 

1. A PHOTOGRAPHIC SILVER HALIDE EMULSION CONTAINING A QUATERNARY AMMONIUM SALT HAVING A GENERAL FORMULA OF THE CLASS CONSISTING OF 